1. Field of the Invention
This invention relates generally to water riding craft, and particularly to a watercraft which is steered and propelled by one riding the watercraft.
2. Description of the Prior Art
It is well known to use a substantially planar body to ride waves. Because the waves usually are found in surf adjacent a shoreline, such sport is generally referred to as "surfing" and the bodies used as "surfboards". Normally, a "surfer", as the board riders are called, stands upright on the board and steers same by the positioning of feet and placement of weight relative to the board as it is being propelled by a wave. It has been proposed, however, to enhance steering of surfboards by provision thereon of a rudder. For example, U.S. Pat. No. 3,747,138, issued July 24th, 1973 to D. R. Morgan, discloses a hydrofoil surfboard construction in which the nose, or forward, hydrofoil may be a steerable foil. This known arrangement contemplates positioning the steerable foil by a pedal actuated by the feet of a surfer standing upright in the conventional manner on a wave propelled board.
It is advantageous, however, to permit the surfer to assume a sitting or prone position on the board in order to improve the stability of the watercraft. Further, it has been proposed to provide such boards with propulsion systems which permit the board to be used in calm, safer, water. Accordingly, U.S. Pat. No. 3,199,485, issued Aug. 10th, 1965 to D. S. Snider, discloses a sailing surfboard incorporating a rudder and tiller to permit steering of the board by one in a sitting position thereon, while U.S. Pat. No. D196,947, issued Nov. 19th, 1963 to F. I. Churchman, shows a board termed a water sled and provided with a nose rudder positionable by one laying prone on the board.
A major disadvantage of the latter two mentioned devices, however, is that they do not readily permit execution of "fish-tailing" movements by a rider of the device. Although the steering foils will assist in orienting the board relative to a wave propelling the board, or to a propelling wind, they do not readily permit the successive side-to-side turning movements frequently performed by an upright surfer and which cause the board to fishtail as it moves along. More importantly, neither of these arrangements permits the rider to control the propulsion of the board in a totally satisfactory manner.
U.S. Pat. No. 1,767,811, issued June 24, 1930 to P. M. Pollard, discloses a surfboard having a downwardly disposable flap intended to present an increased surface area to a wave propelling the board, while U.S. Pat. Nos. 3,194,286, issued July 13th, 1965 to R. B. Anderson, and 3,256,850, issued June 21st, 1966 to C. H. Bramson, discloses surfboards provided with flippers which can be used by a rider to propel the board.
It also has been proposed to provide ships with fore-and-aft disposed plural rudder arrangements to improve the steerability of large, slow moving, cumbersome vessels, especially in harbors and other crowded areas. Examples of such arrangements can be found in U.S. Pat. Nos.: 367,771, issued Aug. 3rd, 1887 to J. C. Witmer; 2,251,133, issued July 29th, 1941 to H. H. Horstman; 2,972,324, issued Feb. 21st, 1961 to C. Williams; and 3,080,845, issued Mar. 12th, 1963 to E. G. Pollak.